Gas storage and release using piezoelectric materials

ABSTRACT

Embodiments are described that generally relate to the storage and release of a gas using piezoelectric materials.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of and claims priority to U.S. patentapplication Ser. No. 12/488,200 filed Jun. 19, 2009 entitled “GasStorage and Release Using Piezoelectric Materials” now U.S. Pat. No.8,197,579 and issued on Jun. 12, 2012, the entire contents of which areincorporated herein by reference.

BACKGROUND Information

Gas storage and release may be desirable in a variety of applications,such as fuel cells, materials or semiconductor processing ormicro-electro-mechanical systems, for example. In some instances, it maybe necessary to release gases quickly, accurately or at a high pressure.Current methods for storing and releasing gases may be difficult, energyintensive, or uneconomical for some applications.

BRIEF DESCRIPTION OF THE DRAWINGS

Subject matter is particularly pointed out and distinctly claimed in theconcluding portion of the specification. The foregoing and otherfeatures of the present disclosure will become more fully apparent fromthe following description and appended claims, taken in conjunction withthe accompanying drawings. Understanding that these drawings depict onlyseveral embodiments in accordance with the disclosure and are,therefore, not to be considered limiting of its scope, the disclosurewill be described with additional specificity and detail through use ofthe accompanying drawings.

In the drawings:

FIG. 1 illustrates an example device for storing and releasing a gas;

FIG. 2 illustrates an example device for storing and releasing a gas;

FIG. 3 illustrates an example system for storing and releasing a gas;

FIG. 4 illustrates a flowchart of an example method for storing andreleasing a gas; and

FIG. 5 illustrates a flowchart of an example method for storing andreleasing a gas, all arranged in accordance with at least someembodiments of the present disclosure.

DETAILED DESCRIPTION

The following description sets forth various examples along withspecific details to provide a thorough understanding of claimed subjectmatter. It will be understood by those skilled in the art, however, thatthe claimed subject matter may be practiced without some or more of thespecific details disclosed herein. Further, in some circumstances,well-known methods, procedures, systems, components and/or circuits havenot been described in detail in order to avoid unnecessarily obscuringclaimed subject matter. In the following detailed description, referenceis made to the accompanying drawings, which form a part hereof. In thedrawings, similar symbols typically identify similar components, unlesscontext dictates otherwise. The illustrative embodiments described inthe detailed description, drawings, and claims are not meant to belimiting. Other embodiments may be utilized, and other changes may bemade, without departing from the spirit or scope of the subject matterpresented here. It will be readily understood that the aspects of thepresent disclosure, as generally described herein, and illustrated inthe figures, may be arranged, substituted, combined, and designed in awide variety of different configurations, all of which are explicitlycontemplated and make part of this disclosure.

This disclosure is drawn, inter alia, to methods, apparatus, and systemsrelated to gas storage and release using piezoelectric metal-organicframework materials.

In a variety of applications, it may be necessary to store and supply agas. For example, the storage and release of hydrogen or other fuels orgases may be an important aspect of fuel cell applications or fueldelivery applications in a wide variety of implementations such as, forexample, automobiles, hand held devices (such as cell phones, gamingdevices or personal digital assistants), laptop computers or industrialapplications. In other examples, the delivery of a gas at substantiallyprecise pressure or volume may be important for materials processing,chemicals processing or semiconductor processing. In some examples, thedelivery of a substantially precise pressure using a gas may beimportant for a variety of implementations, such as, for example,pneumatics systems, motion devices, measurement devices ormicro-electro-mechanical system implementations.

In various embodiments, a gas may be provided for storage and release.In some embodiments, a piezoelectric metal-organic framework (MOF)material may be provided for storage and release of the gas. In someexamples, the piezoelectric metal-organic framework material may becharacterized as a non-centrosymmetric metal-organic framework. In someexamples, the piezoelectric metal-organic framework material may respondto an applied electric field with a net stress throughout the materialthat may at least partially change its size, shape or geometry such thatat different electric field strengths, the material may have differentgas sorption characteristics. In an example, the piezoelectricmetal-organic framework material may readily adsorb the gas with noapplied electric field, such that the material may be substantiallyadsorptive in its relaxed state. In such examples, an applied electricfield may substantially release the adsorbed gas. In some examples, therelease of the stored gas may be responsive to the magnitude of theapplied electric fields such that an electric field with a greatermagnitude causes more gas to be released. Such systems may allow for theaccurate modulation of an applied pressure or an amount of released gasbased at least in part on a variation in electric field strength, whichmay be controlled to a substantially precise degree.

In other examples, the piezoelectric metal-organic framework materialmay adsorb a gas with an applied electric field and may release the gaswhen the electric field is removed or the field strength is lowered. Insome examples, the piezoelectric metal-organic framework material mayselectively adsorb a gas based at least in part on the magnitude of theapplied electric field such that one type of gas is adsorbed at onefield strength and another type of gas is adsorbed at another fieldstrength.

In some embodiments, the piezoelectric metal-organic framework materialmay be provided in a storage and release unit that may includeelectrodes for applying an electric field to the material. The materialmay be provided in a vessel that may include a gas port. The gas portmay lead, by piping, for example, to an optional control valve. Theelectrodes may be coupled by connectors to a power supply which may becoupled to a controller. The power supply, under direction of thecontroller, may provide power to produce the electric field to store andrelease the gas. The storage, release and control of the gas may beconfigured for a variety of implementations. The units and correspondingpiezoelectric metal-organic framework material(s) may be configured in avariety of ways, such as a relatively thin sheet of material sandwichedbetween electrodes, a rolled sheet of material and electrodes, a blockof material coupled to electrodes, or the like.

In various examples, any number of storage and release units may beprovided. The units may be independently controlled or they may becontrolled together. In some examples, the outputs from the units may becombined through a manifold such that several units may provide a singlegas output port. Such implementations may provide for larger gas outputswhile providing relatively thin or small piezoelectric metal-organicframework material units that may be controllable at lower voltages, forexample. In some examples, the units may be in parallel electrically. Inother examples, the units may be in series electrically. In someexamples, the units may share electrodes with adjacent units. The unitsmay be provided or implemented in a wide variety of configurations basedat least in part on application parameters, such as, for example, thevolume or pressure of gas to be provided or the necessary precision ofthe gas delivery system.

FIG. 1 illustrates an example device for storing and releasing a gasarranged in accordance with at least some embodiments of the presentdisclosure. As illustrated in FIG. 1, a gas storage and release device100 may include one or more piezoelectric metal-organic frameworkmaterial 110, an electrode 120 and/or an electrode 125. Gas storage andrelease device 100 may also include a connector 130 and a connector 135,which may be coupled to a power supply, which is not shown in FIG. 1 forthe sake of clarity.

A gas may be introduced to piezoelectric metal-organic frameworkmaterial 110 in any suitable manner. In some examples, gas storage andrelease device 100 may be introduced to a volume or an enclosedcontainer containing a gas to be stored in the gas storage and releasedevice or to be removed from the volume or container. In other examples,device 100 may be in a volume or vessel and a gas may be piped or pumpedinto the volume for storage.

The gas or gases to be stored may include any suitable gas, such as, forexample, hydrogen (H₂), carbon dioxide (CO₂), ammonia (NH₃), borontrifluoride (BF₃), aluminum trifluoride (AlF₃), or the like. Thepiezoelectric metal-organic framework material may be chosen based atleast in part on the gas or mixture of gases to be adsorbed.

In some examples, piezoelectric metal-organic framework material 110 maystore gas with little or no electric field applied to piezoelectricmetal-organic framework material 110. In such examples, the gas may bereleased when an electric field is applied to the piezoelectricmetal-organic framework material. A piezoelectric metal-organicframework material with little or no electric field applied to it may becharacterized as being in a relaxed state. In other examples, a gas maybe stored while an electric field is applied and the gas may be releasedwhen some or all of the electric field may be released from thepiezoelectric metal-organic framework material.

In some examples, based at least in part on the geometry of themetal-organic framework, a large amount of adsorptive surface area maybe provided in a relatively small volume. For example, the piezoelectricmetal-organic framework material may have a substantially porousstructure or structures that may provide substantial gas storagecapacity in a relatively small volume. In some examples, the ratio ofthe volume of stored gas at about standard temperature and pressure tothe volume of the metal-organic framework used to store that volume ofgas may be in the range of about one-hundred (100) to about one thousandtwo-hundred (1200) or more. In some examples, the piezoelectricmetal-organic framework material may provide for six (6) or more weightpercent storage of hydrogen (on a materials basis). In some examples,the piezoelectric metal-organic framework material may change itsgeometry by about one percent under an applied electric field. In someexamples, the piezoelectric metal-organic framework material may providegas storage at relative low pressures. In some example, thepiezoelectric metal-organic framework material may provide gas storageat about room temperature and/or pressure. In other examples, the gasmay be stored at a pressure and/or temperature above room temperatureand pressure.

Piezoelectric metal-organic framework material 110 may include anymaterial or combination of materials that may change its gas adsorptionproperties in response to an applied electric field. The piezoelectricmetal-organic framework material may be constructed from a diverse setof building blocks and, in some examples, the final material may beconstructed to include various functionalities and characteristics, suchas, gas sorption, gas selectivity, piezoelectric properties, densityproperties, weight properties, or the like. In some examples, theelectric field may change the shape, size or geometry of thepiezoelectric metal-organic framework material such that the materialmay store or release a gas.

Piezoelectric metal-organic framework material 110 may include anysuitable material that may store and/or release a gas in response to anelectric field. In some examples, piezoelectric metal-organic frameworkmaterials may include metal ions or clusters and organic moleculesformed in a crystalline structure. In various examples, piezoelectricmetal-organic framework material 110 may be characterized as anon-centrosymmetric material. In some examples, the piezoelectricmetal-organic framework material may include a porous crystallinematerial, such as, for example, MOF-177, MOF-74 or a MOF-74 frameworkstructure with open Zn²⁺ sites. In other examples, the piezoelectricmetal-organic framework material may include a metal-organic frameworkwith coordinately unsaturated metal centers. In other examples, thepiezoelectric metal-organic framework material may include a 2D laminarmultiferroic metal-organic framework, such as, for example, a 2D laminarhomochiral metal-organic framework. In various examples, the 2D laminarhomochiral metal-organic framework may be any metal-organic frameworkhaving the chemical formula (Lig)₂Tb(H₂O)₂(ClO₄), such that Ligrepresents any suitable ligand, such as, for example, any homochiralligand, a lactate ligand, oxalic acid, malonic acid, succinic acid,glutaric acid, phthalic acid, isophthalic acid, terephthalic acid,citric acid, trimesic acid, 1,2,3-triazole, pyrrodiazole, squaric acidor the like. In other examples, the piezoelectric metal-organicframework material may include a diamond-like metal-organic frameworksuch as, for example, Cd(Imazethapyr)₂, which may be crystallized in anon-centrosymmetric space group. In other examples, the piezoelectricmetal-organic framework material may include any homochiralmetal-organic framework such as, for example, (cyanobenzylquinidinium)Cu^(|) ₃(CN)₂Br, (cyanobenzyl cinchonidinium)Cu^(|)_(2.5)(CN)₂Br_(1.5) or the like.

Any volume of piezoelectric metal-organic framework material providedmay be provided based at least in part on the amount and/or pressure ofgas to be stored and/or supplied and the adsorption capacity of thepiezoelectric metal-organic framework material. In some examples thevolume may be in the range of about one (1) to one-hundred (100) cubicmicrons. In other examples, the volume may be in the range of aboutone-hundred (100) cubic microns to one (1) cubic centimeter. In otherexamples, volumes in the range of one (1) cubic centimeter to ten (10)liters may be provided. In an example, a volume of about ten (10) toeighty (80) liters may be provided.

As shown, piezoelectric metal-organic framework material 110 may besandwiched between electrodes 120, 125. The thickness of piezoelectricmetal-organic framework material 110 may be any suitable thickness and,in some examples, may be in the range of about one (1) micron to abouttwenty (20) centimeters, or more. In some examples, the thickness may bein the range of about ten (10) microns to about one-hundred (100)microns. In some examples, the thickness may be in the range of aboutone-hundred (100) microns to about one (1) centimeter. In otherexamples, the thickness may be in the range of about one (1) centimeterto about ten (10) centimeters. As will be discussed further below, avariety of configurations may be available for the piezoelectricmetal-organic framework material and the electrodes, and gas storage andrelease units may be provided in a variety of configurations dependingon the gas storage and delivery implementation.

Electrodes 120, 125 may include any suitable conductive material ormaterials. In some examples, the electrodes may include metals such as,for example, aluminum (Al), copper (Cu), or the like. The electrodes maybe electrically coupled to the piezoelectric metal-organic frameworkmaterial in any manner such that they may apply an electric field to thepiezoelectric metal-organic framework material. In some examples, theelectric coupling may include the electrodes being substantially incontact with the piezoelectric metal-organic framework material. Inother examples, the electric coupling may include the electrodes beingadjacent to, but not in direct physical contact with, the piezoelectricmetal-organic framework material. In some examples, the electriccoupling may include another material or materials between the electrodeand the piezoelectric metal-organic framework material.

As shown in FIG. 1, in some examples, the electrodes may be providedalong a portion of the sides of the piezoelectric metal-organicframework material and the electrodes may be about the same size andthickness. However, one of ordinary skill in the art, in light of thepresent disclosure, will recognize that a variety of otherconfigurations may be used without departing from the spirit or scope ofthe claimed subject matter. In some examples, the electrodes may runalong an entire length of the sides of a piezoelectric metal-organicframework material. In some examples, the electrodes may be differentsizes, thicknesses and/or materials. As shown, in some examples, twoelectrodes may be provided. In other examples, additional electrodes maybe provided. In some examples, the piezoelectric metal-organic frameworkmaterial may be sandwiched between electrodes and the layers may be in aspiral shape. In other examples, multiple layers of piezoelectricmetal-organic framework materials may be layered between multipleelectrodes.

In some examples, the electrodes may be gas permeable. Gas permeableelectrodes may include any suitable gas permeable material(s) and/orconfiguration. In some examples, the gas permeable electrodes mayinclude holes to allow gas permeation. In other examples, the chosenmaterials may be permeable to the gas being stored. In some examples,the electrodes may be substantially thin such that they allow gaspermeation. In some examples, gas permeable electrodes may be arrangedto provide additional surface area for the storage and release of thestored gas. In other examples, the piezoelectric metal-organic frameworkmaterial may be substantially encapsulated by the electrodes and/orother encapsulating material(s) such that gas permeable electrodes areconfigured to provide for the storage and release of the gas.

As discussed, gas storage and release device 100 may be introduced to agas for adsorption in any suitable manner. In some examples, gas storageand release device 100 may be portable and may provide for flexibilitysuch that the device may be easily placed in and/or removed from acontainer. For example, gas storage and release device 100 may beintroduced to a tank of gas to adsorb the gas and may then be removedfrom the tank. The device may then be used to transport the gas, forexample. In some examples, a device may be adapted to provide for theremoval of gas from a volume and may allow for the gas to be disposed ofat another site. Gas storage and release device 100 may also beintroduced to a container or site for release of the gas in any suitablemanner. For example, gas storage and release device 100 may be added toa container or vessel where gas release is desired or it may be attachedto a device for the release of a gas.

As discussed, gas storage and release device 100 may include connector130 and connector 135, which may be adapted to electrically couple orconnect gas storage and release unit 110 to a power supply. The powersupply may apply a voltage to the electrodes, as is discussed furtherbelow. The connectors may be provided in a variety of configurationssuch as, for example, discrete wires or conductive traces on a substrateor circuit board. In some examples, the gas storage and release devicemay be provided in a vessel for controlling the release of the gas andfor connection to a device for release in various implementations.

In some examples, piezoelectric metal-organic framework material 110 andelectrodes 120, 125 may be provided in or on a substrate. In someexamples, the piezoelectric metal-organic framework material andelectrodes may be provided as a solid state device. In some examples,connectors 130, 135 may be provided as conductive traces in or on thesubstrate and a discrete device or unit may be provided. In someexamples, the device may be provided as a board level component. In someexamples, connections to connectors 130, 135 may be made through pinconnections.

In various examples, multiple piezoelectric metal-organic frameworkmaterial and electrode units may be provided. In such examples, multipleconnectors may also be provided. In some examples, the units may becoupled in series electrically. In other examples, the units may becoupled in parallel electrically. In some examples, the units may haveindependent connections to a power supply such that the units may beoperated independently.

FIG. 2 illustrates an example device for storing and releasing a gasarranged in accordance with at least some embodiments of the presentdisclosure. Piezoelectric metal-organic framework material portions maybe adapted to share electrodes.

Piezoelectric metal-organic framework materials 230, 232, 234, 236 mayinclude any of the materials discussed above with reference to FIG. 1.In some examples, the piezoelectric metal-organic framework materialsmay be the same. In other examples, some or all piezoelectricmetal-organic framework materials may be different. As shown, electrodes222, 224, and 226 may be shared electrodes. Such a configuration mayallow for fewer electrode connections and fewer connectors. Theconnectors 260, 262, 264, 266, and 268 may include any of the materialsor configurations as discussed with reference to FIG. 1. The connectorsmay be connected to a power supply that may provide voltages such thatelectric fields are provided to the piezoelectric metal-organicframework materials. In some examples, the supplied voltages may be thesame while in other examples, they may be different. In some examples,multiple connectors may be combined into a single wire or trace beforereaching the powers supply. In some examples, gases may be provided fromthe piezoelectric metal-organic framework materials simultaneously. Inother examples, gases may be provided from the piezoelectricmetal-organic framework materials independently. In an example, gas fromone piezoelectric metal-organic framework material may be exhausted andeach piezoelectric metal-organic framework material may be exhausteduntil the device is exhausted.

FIG. 3 illustrates an example system for storing and releasing a gasarranged in accordance with at least some embodiments of the presentdisclosure. As illustrated in FIG. 3, a gas storage and release system300 may include a gas storage and release unit 305. Gas storage andrelease unit 305 may include one or more of a piezoelectricmetal-organic framework material 310, an electrode 320 and/or anelectrode 325. Gas storage and release unit 305 may be provided in avessel 340 having a port 350. Port 350 may provide for the introductionand release of a gas to piezoelectric metal-organic framework material310. Port 350 may be coupled to a section of pipe and a valve 360.Another portion of pipe may lead from valve 360 in a direction of gasdelivery 370. A void 345 may be provided for expansion of metal-organicframework material 310 and/or for preloading pressure to valve 360. Gasstorage and release system 300 may also include a connector 330 and aconnector 335, which may be electrically coupled to a power supply 380.An optional controller 390 may be coupled to power supply 380 by aconnector 385.

Vessel 340 may include any suitable material for storing a gas. In someexamples, vessel 340 may be provided as a stand alone unit. Electrodes320, 325 may be a part of the vessel or attached either internally orexternally to the vessel in any manner that may provide an electricalcoupling to piezoelectric metal-organic framework material 310 such thatan electric field may be applied to the piezoelectric metal-organicframework material. The other components may be provided as discretecomponents, including, for example, couplers 330, 335 being wires andpower supply 380 and optional controller 390 being discrete devices.

In other examples, vessel 340 may be attached to a mounting substrate orit may be formed in a substrate as a part of a micro-electro-mechanicalsystem. In such examples, electrodes 320, 325 may be formed on thesubstrate and coupled either internally or externally to the vessel inany manner that may provide an electrical coupling to piezoelectricmetal-organic framework material 310 such that an electric field may beapplied to the piezoelectric metal-organic framework material. The othercomponents may be provided in any suitable manner. In some examples,connectors 330, 335 may be discrete wires or traces on a substrate orcircuit board. In some examples, vessel 340 and port 350 may bestructures formed in or on the substrate. Valve 360 may be provided inor on the substrate or it may be provided as an external device separatefrom the substrate and connectable by port 350. Power supply 380 andoptional controller 390 may also be provided integral to the substrateor as discrete components. In some examples, gas storage and releaseunit 305 may be provided as a board level device and connections may bemade to it using pin connections. In an example, the unit may providefor a micro fuel cell unit for providing fuel to a variety ofcomponents.

A gas may be introduced to piezoelectric metal-organic frameworkmaterial 310 in any suitable manner, such as, for example, through port350 by opening valve 360. The gas to be stored and/or released mayinclude any gas discussed herein. The piezoelectric metal-organicframework material may be chosen based at least in part on the gas ormixture of gases to be adsorbed and may include any material ormaterials herein.

As discussed, gas storage and release system 300 may include connector330 and connector 335, which may electrically couple to power supply380. The connectors may be provided in a variety of configurations suchas, for example, discrete wires or conductive traces on a substrate orcircuit board.

Power supply 380 may include any suitable power supply module that maysupply power to apply an electric field to the piezoelectricmetal-organic framework material via, for example, connectors 330, 335and electrodes 320, 325. In various examples, the power supply mayinclude a constant voltage source or a constant current source. In someexamples, the power supply may be adapted to provide substantially anyvoltage and/or current within a particular range or ranges of valuessuch that the electric field may be modulated. The voltage supplied maybe based at least in part on system parameters such as, for example, thegas stored and released, the type of piezoelectric metal-organicframework material, the size and thickness of the piezoelectricmetal-organic framework material or the like. In various examples, thesupplied voltage(s) may be in the range of about one (1) volt to aboutten (10) kilovolts or more. In an example, the power supply may beadapted to operate in response to signals from controller 390.

Controller 390 may be any device that may control power supply 380. Insome examples, controller 390 may include one or more of a processor, amemory, input/output devices, display devices and/or related circuitry.In some examples, controller 390 may be provided as a computer orworkstation. In other examples, controller 380 may be provided as adedicated integrated circuit. Controller 390 may be connected to otherdevices (not shown) that may be adapted to provide data to controller390, such as, for example, feedback, system requests, ambient parametersor the like. In some examples, controller 390 may be connected to outputdevices, such as, for example, memory devices, printers, monitors, orthe like, such that data may be collected or monitored.

As shown in FIG. 3, a single gas storage and release unit may beprovided in a single vessel. In other examples, multiple gas storage andrelease units may be provided in a single vessel. In some examples,multiple vessels may be provided with each having a single or multiplegas storage and release unit. In other examples, multiple vessels may beprovided with different numbers of gas storage and release units. Invarious examples, about two (2) to about ten (10) vessels may beprovided. In other examples, hundreds or more vessels may be provided.In some examples, the piezoelectric metal-organic framework materialsmay be the same in each vessel. In other examples, the piezoelectricmetal-organic framework materials may be different. In some examples,multiple vessels may be provided that may be configured with a manifoldto combine their outputs to a single output. In other examples, multiplemanifolds may be provided. The multiple gas storage and release unitsmay be provided in any manner as discussed above, such as, for example,electrically in series, electrically in parallel, or configured withshared electrodes as described with reference to FIG. 2.

In some examples with multiple vessels, the power supply may be arrangedto provide the same voltages to each of the piezoelectric metal-organicframework materials. In other examples, the supplied voltages may bedifferent. In some examples, gases may be provided from the vesselssimultaneously. In other examples, gases may be provided from thevessels independently. Such control of gas delivery from the vessels maybe effected by controller 390 and power supply 380 causing electricfields to various vessels. In an example, gas from one vessel may beexhausted and the system may sequentially move to other vessels untilthe system is exhausted.

FIG. 4 illustrates a flow chart of an example method 400 for storing andreleasing gas in accordance with at least some embodiments of thepresent disclosure. Method 400 may include one or more functionaloperations as illustrated by blocks 405, 410, 415, 420, 425, 430, 435,440, 445, and/or 450.

At block 405, a piezoelectric metal-organic framework material may beprovided. Any of the piezoelectric metal-organic framework material(s)as discussed above in any configuration and/or system as discussed abovemay be provided. Processing may continue from block 405 to block 410.

At block 410, a gas may be stored in the piezoelectric metal-organicframework material. Any gas as discussed above may be stored in anymanner as discussed. For example, a gas may be provided by opening avalve and providing the gas into a vessel having the piezoelectricmetal-organic framework material. In an example, the gas may be adsorbedwithout the application of an electric field to the piezoelectricmetal-organic framework material. Processing may continue from block 410to block 415.

At block 415, an electric field may be applied to the piezoelectricmetal-organic framework material (and the stored gas) in any manner asdiscussed above. The electric field may induce or trigger the release ofat least a portion of the gas and may pressurize a vessel and/or avalve. Processing may continue from block 415 to block 420.

At block 420, the valve may be opened to release the gas. As shown, theelectric field may be provided prior to the valve opening such that thegas may be pressurized or pre-pressurized. In other examples, the valvemay be opened and the electric field may be applied substantiallysimultaneously. In other examples, the valve may be opened prior toproviding the electric field. In other examples, no valve may beprovided and the electric field may release the gas. Processing maycontinue from block 420 to block 425.

At block 425, method 400 may be arranged to determine whether the gassupply or release is complete. In some examples, the determination maybe made based on feedback, for example, from the system or unitreceiving the gas. In other examples, the determination may be basedwithout feedback and it may be made on, for example, an elapsed amountof time or a predetermined pressure drop or the like. In any event, ifthe supply of gas is not complete, the valve may remain open and theelectric field application may continue, and the method may continuouslyor periodically return to decision block 425. Processing may remain atblock 425 until the gas supply is complete. Processing may continuedfrom block 425 to block 430 when the supply of gas is complete.

At block 430 the valve (if used) may be closed. Processing may continuefrom block 430 to block 435.

At block 435, the electric field may be removed. Upon removal of theelectric field, at least a portion any remaining gas may be adsorbedinto the piezoelectric metal-organic framework material. Processing maycontinue from block 435 to block 440.

At block 440, the method 400 may be arranged to determine whetheradditional gas is to be released. In some examples, the determinationmay be based on feedback from another system or unit. In other examples,the determination may be based on a predetermined parameter, such as avolume of gas to be released, a counter value that stores the number oftimes gas has been released or the like. If additional gas is to besupplied or released, the method may proceed from block 440 to block 415and the method may be repeated. If no additional gas is to be supplied,then the method may proceed from block 440 to block 445.

At block 445 the method 400 may determine whether additional gas is tobe stored (for example, to recharge the system for additional gasrelease or supply). If additional gas is to be stored, then the methodmay proceed from block 445 to block 410. If additional gas is not to bestored, then the method may proceed from block 445 to block 450, wherethe process may terminate.

FIG. 5 illustrates a flowchart of an example method 500 for storing andreleasing a gas in accordance with at least some embodiments of thepresent disclosure. Method 500 may include one or more functionaloperations as illustrated by blocks 505, 510, 515, 520, 525, 530, 535,540, 545, 550 and/or 555.

At block 505, a piezoelectric metal-organic framework material may beprovided. Any of the piezoelectric metal-organic framework material(s)as discussed above in any configuration and/or system as discussed abovemay be provided. Processing may continue from block 505 to block 510.

At block 510, an electric field may be applied to the piezoelectricmetal-organic framework material. Processing may continue from block 510to block 515.

At block 515, a gas may be stored in the piezoelectric metal-organicframework material. Any gas as discussed above may be stored in anymanner as discussed. For example, a gas may be provided by opening avalve and providing the gas into a vessel having the piezoelectricmetal-organic framework material. In some examples, the piezoelectricmetal-organic framework material may selectively adsorb a gas based atleast in part on the magnitude of the applied electric field such thatone type of gas is adsorbed at one field strength and another type ofgas is adsorbed at another field strength. In such examples, the appliedelectric field may have to be substantially tuned at based at least inpart on the type of gas to be stored. Processing may continue from block515 to block 520.

At block 520, at least a portion of the applied electric field may beremoved in any manner as discussed above. The removal of the electricfield or a portion of the electric field may release at least a portionof the gas and may pressurize a vessel, a valve or the like. Processingmay continue from block 520 to block 525.

At block 525, the valve may be opened to release the gas. As shown, inan example, the electric field may be released or removed prior to thevalve opening such that the gas may be pressurized or pre-pressurized.In some examples, the valve may be opened and the electric field may beremoved or reduced substantially simultaneously. In other examples, thevalve may be opened prior to removing or reducing the electric field.Processing may continue from block 525 to block 530.

At block 530, method 500 may determine whether the gas supply or releaseis complete. In some examples, the determination may be made based onfeedback, for example, from the system or unit receiving the gas. Inother examples, the determination may be based without feedback and itmay be made on, for example, an elapsed amount of time or apredetermined pressure drop or the like. In any event, if the supply ofgas is not complete, the valve may remain open and the electric fieldapplication may continue, and the method may continuously orperiodically return to decision block 530. Processing may remain inblock 530 until the gas supply is complete. When the supply of gas iscomplete, then processing may continue from block 530 to block 535.

At block 535, the valve (if used) may be closed. Processing may continuefrom block 535 to block 540.

At block 540, an electric field may be applied or reapplied to store thegas. Upon application or reapplication of the electric field, at least aportion any remaining gas may be adsorbed into the piezoelectricmetal-organic framework material. Processing may continue from block 540to block 545.

At block 545, method 500 may determine whether additional gas is to besupplied. In some examples, the determination may be based on feedbackfrom another system or unit. In other examples, the determination may bebased on a predetermined parameter, such as a volume of gas to bereleased, counter value that stores the number of times gas has beenreleased or the like. If additional gas is to be supplied or released,the method may proceed from block 545 to block 520. If no additional gasis to be released, then processing may continued from block 545 to block550.

At decision block 550, method 500 may determine whether additional gasis to be stored (for example, to recharge the system for additional gasrelease). If additional gas is to be stored, then the method may proceedfrom block 550 to block 510 and the method or portions of the method maybe repeated. If additional gas is not to be stored, then the method mayproceed from block 550 to block 555, where the process may terminate.

Although the discussion herein has focused on techniques related to thestorage and release of a gas, the techniques discussed may be extendedto gas purification and separation. For example, a device as discussedabove may be exposed to a gas mixture. The piezoelectric metal-organicframework materials discussed may selectively remove a gas (or gases)from the mixture such that a separation or purification may be achieved.The selective removal of gas may be performed in any manner as discussedabove. The gas removed from the mixture into the piezoelectricmetal-organic framework material may be subsequently released.

Claimed subject matter is not limited in scope to the particularimplementations described herein. Reference in the specification to “animplementation,” “one implementation,” “some implementations,” “otherimplementations,” “an example,” “some examples,” “various examples,” or“other examples” may mean that a particular feature, structure, orcharacteristic described in connection with one or more implementationsor examples may be included in at least some implementations orexamples, but not necessarily in all implementations or examples. Thevarious appearances of “an implementation,” “one implementation,” “someimplementations,” “an example,” “some examples,” “various examples,” or“other examples” in the preceding description are not necessarily allreferring to the same implementations or examples.

In the preceding description, various aspects of claimed subject matterhave been described. For purposes of explanation, specific numbers,systems and/or configurations were set forth to provide a thoroughunderstanding of claimed subject matter. However, it should be apparentto one skilled in the art and having the benefit of this disclosure thatclaimed subject matter may be practiced without the specific details. Inother instances, well-known features were omitted and/or simplified soas not to obscure claimed subject matter. While certain features havebeen illustrated and/or described herein, many modifications,substitutions, changes and/or equivalents will now, or in the future,occur to those skilled in the art. It is, therefore, to be understoodthat the appended claims are intended to cover all such modificationsand/or changes as fall within the true spirit of claimed subject matter.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art may translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity.

It will be understood by those within the art that, in general, termsused herein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to inventions containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations. In addition, evenif a specific number of an introduced claim recitation is explicitlyrecited, those skilled in the art will recognize that such recitationshould typically be interpreted to mean at least the recited number(e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that virtually any disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms. For example, the phrase “A or B” will be understood toinclude the possibilities of “A” or “B” or “A and B.”

What is claimed is:
 1. A method for storing and releasing a gas, themethod comprising: providing a piezoelectric metal-organic frameworkmaterial; adsorbing at least a portion of the gas into the piezoelectricmetal-organic framework material; and applying an electric field to thepiezoelectric metal-organic framework material to release a portion ofthe gas.
 2. The method of claim 1, wherein the piezoelectricmetal-organic framework material comprises one or more of MOF-177,MOF-74, an MOF-74 framework structure with open Zn2+ sites, a 2D laminarhomochiral metal-organic framework, and/or a piezoelectric metal-organicframework material having the chemical formula (Lig)2Tb(H2O)2(ClO4),wherein Lig corresponds to a ligand comprising one or more of oxalicacid, malonic acid, succinic acid, glutaric acid, phthalic acid,isophthalic acid, terephthalic acid, citric acid, trimesic acid,1,2,3-triazole, pyrrodiazole and/or squaric acid.
 3. The method of claim1, wherein the gas comprises one or more of hydrogen, carbon dioxide,ammonia, boron trifluoride, and/or aluminum trifluoride.
 4. The methodof claim 1, further comprising varying a magnitude of the appliedelectric field to vary an amount of gas released from the piezoelectricmetal-organic framework material.
 5. A method for storing and releasinga gas comprising: providing a piezoelectric metal-organic frameworkmaterial; applying an electric field to the piezoelectric metal-organicframework material; adsorbing at least a portion of the gas into themetal-organic framework material during application of the electricfield; and reducing an electric field strength of the electric field torelease at least a portion of the gas.
 6. The method of claim 5, whereinthe piezoelectric metal-organic framework material comprises one or moreof MOF-177, MOF-74, an MOF-74 framework structure with open Zn2+ sites,a 2D laminar homochiral metal-organic framework, and/or a piezoelectricmetal-organic framework material having the chemical formula(Lig)2Tb(H2O)2(ClO4), wherein Lig corresponds to a ligand comprising oneor more of oxalic acid, malonic acid, succinic acid, glutaric acid,phthalic acid, isophthalic acid, terephthalic acid, citric acid,trimesic acid, 1,2,3-triazole, pyrrodiazole and/or squaric acid.
 7. Themethod of claim 5, wherein the gas comprises one or more of hydrogen,carbon dioxide, ammonia, boron trifluoride, and/or aluminum trifluoride.8. The method of claim 5, further comprising: applying a second electricfield to the piezoelectric metal-organic framework material, wherein thesecond electric field has a different magnitude than the first electricfield; and adsorbing at least a portion of a second gas into thepiezoelectric metal-organic framework material during application of thesecond electric field, wherein the second gas is different than the gas.9. An apparatus that is arranged to store a gas and release the gasresponsive to the application of an electric field, the apparatuscomprising: a piezoelectric metal-organic framework material, thepiezoelectric metal-organic framework material configured to adsorb atleast a portion of the gas in response to the application of an electricfield; a power supply; a controller coupled to the power supply, whereinthe controller is arranged to control the application of the electricfield with the power supply; a vessel, wherein the piezoelectricmetal-organic framework material is in the vessel; and a gas port in thevessel, wherein the gas port is arranged to convey the gas when gas iseither released or stored by the apparatus.
 10. The apparatus of claim9, wherein the piezoelectric metal-organic framework material comprisesa non-centrosymmetric piezoelectric metal-organic framework material.11. The apparatus of claim 9, wherein the piezoelectric metal-organicframework material comprises one or more of MOF-177, MOF-74, and/or anMOF-74 framework structure with open Zn2+ sites.
 12. The apparatus ofclaim 9, wherein the piezoelectric metal-organic framework materialcomprises a 2D laminar homochiral metal-organic framework.
 13. Theapparatus of claim 9, wherein the piezoelectric metal-organic frameworkmaterial comprises a piezoelectric metal-organic framework materialhaving the chemical formula (Lig)2Tb(H2O)2(ClO4), wherein Ligcorresponds to a ligand comprising one or more of oxalic acid, malonicacid, succinic acid, glutaric acid, phthalic acid, isophthalic acid,terephthalic acid, citric acid, trimesic acid, 1,2,3-triazole,pyrrodiazole and/or squaric acid.
 14. The apparatus of claim 9, furthercomprising: a second piezoelectric metal-organic framework material. 15.A method of storing and releasing a gas responsive to the application ofan electric field, the method comprising: providing a piezoelectricmetal-organic framework material, the piezoelectric metal-organicframework material configured to adsorb at least a portion of the gas inresponse to the application of an electric field; adsorbing at least aportion of the gas into the piezoelectric metal-organic frameworkmaterial; and applying an electric field to the piezoelectricmetal-organic framework material to release a portion of the gas.